1. Field of the Invention
The invention relates generally to methods of securement such as anchoring one material to another through utilization of an embedment. More particularly, the invention deals with a method of securing a finding to an article of ornamentation and the composite article so formed.
2. Brief Description of the Prior Art
A significant problem in the manufacture of articles of decorative or functional ornamentation such as badges, pins, cufflinks, etc., has been the difficulty in achieving an economical yet satisfactory securement between the article body and a finding such as a pin or post. Many prior approaches toward securement between the main body of the article of ornamentation and the finding employed the use of various adhesive mediums such as solvents, solder, or through interlocking engagements such as the seating of a portion of the finding in a groove or channel or the use of bendable tabs.
Attempts at bonding a metallic element having means for supporting an ornament in wearing position to a thermoplastic ornamentation were exemplified by U.S. Pat. No. 2,014,414, which disclosed the softening of a thermoplastic sheet through the use of heat and compressing the metallic element into the softened surface such that a bead of thermoplastic was formed around the edges of the metallic element. The bead served to interlock the metallic element to the thermoplastic body.
Among the disadvantages inherent in the technique of securement employing a peripheral bead of solidified thermoplastic was that the bead often did not freeform over the peripheral edge of the metallic element and thus only a weak bond resulted. In order to achieve a peripheral overlap of molten thermoplastic beyond the peripheral edge of the metallic element, it was necessary to embed the metallic element deep into the thermoplastic body. Even with increased peripheral flow, optimum bonding was only achieved with a subsequent forming step forcing the beaded edge into a position which overlapped a marginal zone of the element. This was usually accomplished with a heated burnishing tool and tended to result in an unsightly appearance.
A disadvantage of increased penetration of the element into the body to increase the flow of thermoplastic was that care had to be taken if the obverse face of the thermoplastic body was to be engraved. The engraver was required to control the depth of engraving tool penetration so as not to cut too deeply into the body to thereby avoid exposure of the embedded element.
Even with the additional step of burnishing the peripheral bead to achieve an overlap, the bond between the element and the thermoplastic body was subject to dislodgement resulting from nicking or chipping of the bead during use and even from a spreading of the bead without fracture to release the element.